This study examines 10 selected pre-pubertal subjects with IDDM, who have suspected post-hypoglycemic hyperglycemia. The differences in morning blood glucose will be compared following nocturnal hypoglycemia or euglycemia, and related to serum free insulin, epinephrine, norepinephrine, glucagon, growth hormone, cortisol, and beta-hydroxybutyrate concentrations, measured repeatedly during the night.